Bypass o2 sensors

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Pinger

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Not sure on that one but since it was brand new the suburban will hit 97mph and the rpms will be around 3k. Once you hit 98mph it will bog down to about 95mph and repeat the process.
My smart had a speed limiter and it went to that speed then just stopped accelerating.
If I'm not mistaken the od get disabled at that high of rpms and speed.... now btw the guage will say 100mph but from my experience that's how much off the speed is to actual speed. I only found this out when the tuner downloaded my factory specs
I thought I heard something like that - that it would drop into 3rd at close to Vmax. Or, that the required shove on the pedal induced a downshift to 3rd. Seems though that if the throttle pedal isn't on the floor all the way to circa 100 is possible in OD. More plausible in mine with its 4.11 axle. I've seen 85mph in OD a few times and that seems effortless both on the drivetrain and keeping it in a straight line.
 

Nad_Yvalhosert

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Farm trucks OE engine, was a small block 400. It has been through a bunch of engines, but now has a built 632 big block with a ton of NOS.
Yeah, I've been following that thing since before he was famous on TV. Still makes me laugh when the back hatch on the cap lifts open on a launch.
Azn was annoying, but the truck is the greatest sleeper I've seen
 

Ztoxic_Helix

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So I just looked around in Pineville, WV 24874, USA since that's where the OP's location is listed... which btw is only about 3.2 miles at its widest point..

Presume a 0-60 time of... pff let's be generous since she's a Vortec and say 8 seconds.. assume the vehicle weighs in the ballpark of 2800kg.. insert math here

Using that we can come to a rough estimate of 30 seconds for a 0-120, which would a whopping 804 meters of roadway. Let's toss on another 196 meters of stopping distance just to come up with an even 1 mile for simplicity. So now.. at least a 1 mile stretch of privately owned roadway in the OP's listed postal area, that's straight enough to actually achieve all this..

Admittedly it's kinda hard to see all the roads, but I'm pretty sure this happened on the 97 going East out of town.
Why put your actual address
 

Dariusz Salomon

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My smart had a speed limiter and it went to that speed then just stopped accelerating.

I thought I heard something like that - that it would drop into 3rd at close to Vmax. Or, that the required shove on the pedal induced a downshift to 3rd. Seems though that if the throttle pedal isn't on the floor all the way to circa 100 is possible in OD. More plausible in mine with its 4.11 axle. I've seen 85mph in OD a few times and that seems effortless both on the drivetrain and keeping it in a straight line.
I tested Tahoe in Germany and it does drop at around 112-117 if I remember correctly. Limiter kicks in.
 

Mikes98

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I got a 1998 GMC Sierra 1500 5.7 vortex, 4l60e true duals exhaust, but I can’t figure out how to do the o2 sensors, I would much rather bypass them if possible, cause it says there supposed to have 4 o2 sensors, but I can only find the ones for the 2 at the top, my motor just revs up and down at 30, but past 30 runs great till I drop back down to 30 again, and it spits and spudders when I go from dead stop to up hill, but I know there nothing wrong with Tranny, got it up to 120 last night no problem, got mad at and wanted to blow it, done bought 3 transmissions for it
Agree with Kennythewelder.

Your factory ECM is looking for fuel mixture information which is what the O2 sensors provide. You'll have to install the O2 sensors at the stock positions to make the computer happy. If the computer ain't happy ...just like momma ...aint' nobody gonna be happy.

IMHO, unless you've greatly improved the breathing on the intake side of the engine (heads, manifold, intake tract) putting true dual's on a modern computer-controlled truck engine really isn't gonna get you much (other than a really big PITA like you've got yourself into). So me, myself and I would seriously consider ditching the duals for a stock Y-pipe/cat setup, the stock O2 setup, installing a good aftermarket cat back exhaust, ending up with a good running truck and ...having a celebration beer ...or two. But, that's me.

If the truck originally came with a single exhaust (which it probably did), then I would set it up with the stock O2 configuration. You need to do some research to find out what that original configuration was. As part of this research you'll need to find out if the truck is equipped with California emissions ...which could need a different O2 setup than 49-State vehicles. My '98 has CA emissions (5.0L) and has 4 O2 sensors: one in each down tube with one before and one after the cat. Of course all of this is dependent on having cats. If you have cats, then pick one and install the pre and post O2 sensors on it. They make no-weld O2 bungs; just drill the hole. This setup will have the ECM mixture determined by only one bank of cylinders but if the engine is in decent internal condition it should be okay ...my guess. I'm sure someone will straighten me out if I'm wrong.

If you don't have any cats then you need to do some other stuff ($$$$). Gutting a cat-equipped vehicle, IMHO, is more trouble than it's worth as most cats offer very little restriction in exhaust flow. Without the O2 sensors your ECM has no idea how to meter fuel; I'm guessing it's probably running in some kind of limp home mode ...which is why it's running like cr@p. Bypassing/modifying the factory O2 sensor setup will probably require an aftermarket ECM, some savvy tuning of the stock ECM(?) or some other equally expensive gee-gaws. IMHO, this is one of the best functions of the computer; making sure you have the correct fuel mixture all the time and under all driving conditions. Bypassing the system isn't in your best interests.
 
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